Cardoso had been due to start the Tour de France, which begins with the Grand Depart in Dusseldorf on Saturday (July 1).

The International Cycling Union (UCI) has confirmed the rider was notified of an Adverse Analytical Finding for EPO in a sample taken from him on June 18.

"The control was planned and carried out by the Cycling Anti-Doping Foundation, the independent body mandated by the UCI, in charge of defining and implementing the anti-doping strategy in cycling," a statement from the UCI said.

"The rider has the right to request and attend the analysis of the B-sample.

"In accordance with UCI Anti-Doping Rules, the rider has been provisionally suspended until the adjudication of the affair."

Cardoso, who had been set to support Alberto Contador at the Tour de France, claimed his innocence on Facebook.

The 32-year-old expressed his hope that a B-sample will clear him of wrongdoing.

“Getting the chance to ride at the pinnacle of professional cycling is the greatest honour I could ever hope for and I was looking forward to doing my best for my team and myself at the Tour," Cardoso stated.

"I believe in clean sport and have always conducted myself as a clean athlete, but I realize that this news puts a dark cloud on not just myself but also on our sport and my team, team-mates and staff.

"I am fully aware that I will be presumed to be guilty, but it's important to me to say that I am devastated by this news and I wanted to state that I have never taken any illegal substances.

Cardoso added: "I've always tried to be a constructive influence in the peloton and on young, aspiring cyclists.

"It is my great hope that the B sample will come back as negative and clear me of any wrongdoing."

Trek-Segafredo have confirmed Cardoso’s suspension and have called up Spain’s Haimar Zubeldia to their Tour de France squad, with the 40-year-old set to ride the Grand Tour for the 16th time in his career.

"It is with deep disappointment that we have just learned that our rider, Andre Cardoso, has tested positive for a prohibited substance," a Trek-Segafredo statement read.

"In accordance with our zero-tolerance policy, he has been suspended immediately.

"We hold our riders and staff to the highest ethical standards and will act and communicate accordingly as more details become available."

Following the Grand Depart, the Tour de France will run until July 23, when racing is due to finish along the Champs-Élysées in Paris.

The race is part of the UCI WorldTour.